Slippage reducing pulley



Aug. 13, 1957 c. BORNER SLIPPAGE REDUCING PULLEY 4 Sheets-Sheet 1 Filed Feb. 12, 1954 VENTOR. RHER N CHRISTIAN 3 1957 c. BORNER 2,802,366

SLIFPAGE REDUCING PULLEY Filed Feb. 12, 1954 4 Sheets-Sheet 3 75.11. INVEIVTOR.

Cfr/ZIrT/fim gam Aug. 13, 1957 c, BORNER SLIPPAGE REDUCING PULLEY 4 Sheets-Sheet 4 Filed Feb. 12, 1954 R me V H N I W W\ M MN m .C

United States Patent Ce SLIPPAGE REDUCING PULLEY Christian Burner, Erlenbach (Main), Germany, assignor, by mesne assignments, to American Enka Corporation, Enka, N. C., a corporation of Delaware Application February 12, 1954, Serial No. 409,987 .Claims priority, application Germany February 14, 1953 19 Claims. (Cl. 74230.5)

The present application is a continuation-in-part application of my copending application Serial No. 380,166, filed September 15, 1953, and now abandoned.

The present invention relates to pulleys, and more particularly to a slippage reducing or preventing divided roller or pulley for guiding a filament, thread or rope along a been wound several times around the pulley. However,'

all these attempts have not been completely successful since all filaments stretch at a certain tension and cannot be tensioned beyond a predetermined extent without breaking. Consequently before the filament is tensioned sufliciently to prevent slippage, the filament breaks.

The guiding of the filament in several loops around the pulley is particularly undesirable in the use of rollers or pulleys with artificial fibers, although slippage is not completely prevented thereby. It will be understood that in the textile industry the slippage of natural or artificial filaments on guiding rollers is a decided disadvantage.

The same is true for pulleys which are used in transmissions in which the slippage of the belts is highly disadvantageous and causes losses.

It is one object of the present invention to overcome the disadvantages of the known constructions for reducing the slippage of filaments and ropes on pulleys and other rollers, and to provide a pulley for reducing or eliminating the slippage of a flexible elongated means such as a rope or filament running over the same.

It is another object of the present invention to provide a pulley which consists of two coaxial pulley discs, each pulley disc carrying a set of peripheral projections defining a Wavy path for a flexible rope or thread.

It is still another object of the present invention to provide means supporting the two pulley discs for movement in axial direction toward and away from each other for changing the deflection of a flexible means guided on the peripheral projections.

It is yet another object of the present invention to provide radially projecting guiding faces for guiding the flexible means at points intermediate adjacent peripheral projections.

It is an important object of the present invention to provide a pulley or roller having a wavy groove for stretching a filament or thread located in the groove.

It is a further object of the present invention to provide a roller having a groove permitting smooth running of a tensionedfilament supported in the groove.

With these objects in view, the present invention mainly consists in a pulley having an annular peripheral face and comprising two sets of circumferentially spaced guiding means on the annular peripheral face, the guiding means of one of the sets being arranged staggered relative to the'guiding means of the other of the sets, the guiding 2,802,366 Patented Aug. 13,1957

means having guiding faces for guiding a flexible elongated means, the guiding faces of each set of guiding means projecting alternately in opposite axial directions into the spaces between the guiding means of the other set of guiding means, and a set of circumferentially spaced radially projecting face portions on the annular peripheral face, each of the radially projecting face portions being located circumferentially spaced from and intermediate the guiding faces of adjacent guiding means of the two sets of guiding means and adapted to support the flexible elongated means.

Preferably the pulley consists of two coaxial pulley discs, and means are provided for guiding at least one of the pulley discs for movement in axial direction toward and away from the other pulley disc whereby the guiding faces of one pulley disc project into opposite spaces be tween the guiding faces of the other pulley disc to different degrees for adjusting the deflection of a flexible rope or thread guided between the guiding faces and supported by the radially projecting face portions.

More particularly the present invention consists in a pulley formed with an annular wavy groove having a plurality of spaced crest portions alternately projecting in opposite directions, the groove having an annular bottom face including spaced projecting bottom face portions, each of the projecting bottom face portions being located intermediate and spaced from two adjacent crest portions, the groove having an outwardly flaring and widening cross-section.

The comparatively simple construction of a roller or pulley according to the present invention permits in a very surprising manner a slippage-free drive which may be applied to transmissions employing ropes, as Well as for the transport or stretching of natural or newly spun artificial fibers.

It is apparent that the width of the wavy groove according to the present invention should be adapted to the thickness of the rope or filament located therein, or to the titer of the transported filament or synthetic fiber. The groove must be so dimensioned as to hold the running filament or thread without clamping or snagging.

Preferably the pulley according to the present invention, consists of acid-resistant material, such as glass or porcelain.

According to a preferred embodiment of the present invention, the pulley consists of two coaxial pulley discs which are provided with axially projecting claws which interengage in a manner similar to a claw coupling. Means are provided for determining the axial spacing of the two pulley discs whereby the deflection of the flexible rope or thread can be changed.

By adjusting the axial overlapping of the guiding means it is possible to vary the friction exerted by the pulley on the rope, and to adapt the friction to the titer of the transported filament or thread. 7

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as: to its construction and its method of operation, together with additional objects and'advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. l is an isometric View of a pulley according to: the present invention;

Fig. 2 is a fragmentary cross-sectional view on line 2-2 in Fig. 3;

Fig. 3 is an enlarged detail of the periphery of a pulley according to the present invention;

Fig. 4 is a fragmentary cross-sectional view on line: '4-4 in Fig. 3;

Fig. 5 is a developed sectional view taken in longitudinal direction of the groove on line 55 in Fig. 3;

Fig. 6 is an isometric fragmentary sectional view taken on line 55 in Fig. 3; Fig. 7 is an isometric View of a pulley consisting of two separable pulley discs; I

Fig. 8 is a detail of the periphery of a pulley according to Fig. 7;

Fig.9 is a cross-sectional view on line 99 in Fig. 8;

Fig. 10 is a cross-sectional view on line 1010 in Fig. 8;

Fig. 11 is a sectional View taken in peripheral direction along a rope on line 11-11 in Fig. 8;

Figs. 12,1211 and 12b are cross-sectional views taken on lines 1212, 12a12q, and 12b12b, respectively,

in Figsf1 3, 13a and 13b; and Figs. 13, 13a and 13b are plan views of details.

Referring now to the drawings, and more particularly to Figs. 1 to 6, which show an integral pulley according to the present invention, the wavy groove 2 in the pulley or roller 6 has an outwardly flaring cross-section as can be best seen in Figs. 2 and 4, and is bounded by lateral faces 3 and 4 which have alternately arranged projecting and receding portions. As is best seen from Fig. 3, the projecting portions 3a of the lateral faces 3 are located opposite. the receding portions 4b of the other lateral face 4, while the projecting portions 4a are located opposite the receding portions 312. It is apparent that the wavy groove has crest portions which alternately project in opposite directions.

A filament, thread, or rope 1 is guided on the bottom face of the wavy groove 2 and alternately abuts on the projecting portions 4a and 3a of the lateral faces of the groove due to the tension of the filament.

The bottom face 5 of the groove is not cylindrical with respect to the axis of the pulley, but includes spaced radially projecting bottom face portions Sa which are located intermediate the crest portions of the wavy groove, and in other words intermediate the projecting face portions 3a and 4a of the lateral faces 3 and 4.

As may be seen from Figs. 2 and 3, the projecting bottom face portions 5a are each spaced a substantial distance from the crests 3a and 4a, and each of these projecting bottom face portions 5a has in a circumferential direction a dimension which is substantially smaller than the. distance between each crest 4a and the succeeding crest 3a. Furthermore, as is evident from Figs. 2 and 3, some of the projecting bottom face portions 5a extend from the lateral face 4 toward the lateral face 3 and some of theseprojecting bottom face portions 5a extend from the lateral face3 toward the lateral face 4, the series of projecting bottom face portions 5a alternately extending from the lateral faces 3 and 4. As may be seen from Fig. 2, the projecting. bottom face portion 5a which extends from the face 4 toward the face 3 has an outer convex face which is directed toward the face 3 and which approaches the bottom of the groove as it approaches the face 3. In the same way, as may be seen in dotted lines in Fig. 2, the projecting bottom face portions 5a which extend from the face.3 toward the face 4 have an outer convex surface directed toward the face 4 and curved downwardly from the face 3 toward the bottom of the groove as they approach the face 4.

Consequently the filament which is guided in the wavy groove, is, consecutively engaged by a projection 4a, by a projecting bottom face portion 5a, and by a projection 3a. At the points where the filament engages the projections3a and 4a., the filament is spaced from the bottom face of the groove, while it is supported on the projecting bottom face portions 511 at points in which it does not engage the lateral faces of the wavy groove.

The filament, or rope, is held on the projections 3a andAa, respectively with an increased friction, while any clamping, snagging or catching of the filament is prevented by the fact that it does not touch the bottom face of the groove at the points at which it is laterally supported by the projections 3a and 4a. On the other hand the filament is frictionally engaged by the three face's bounding the groove so that it runs in the groove without having any slippage.

The wavy shape of the groove corresponds substantially to a sine curve, and it will be understood that the radius of curvature of the projections 3a and 4a must be adapted to the properties of the filament, thread, or rope which is driven. A harder and stifiier material requires a greater radius of curvature, while on the other hand a softer material requires a smaller radius of curvature for slippage-free run.

Therefore, ditferent pulleys are required for different materials which would require storing of a number of integral pulleys for different purposes. To overcome this disadvantage, a preferred embodiment of the present invention provides a pulley consisting of two pulley discs which are arranged movable in axial direction for changing the sinus-shaped path of the rope or filament.

Referring now to Fig. 7, the modified pulley consists of two coaxial pulley discs 6a and 6b which are clamped to each other by attaching means '7 which are illustrated to be bolt and nut means. It will be apparent that other attaching means may be provided for holding the pulley discs together. Each pulley disc is provided with fingers, the pulley disc 6a having the fingers 11, and the pulley disc 6b having the fingers 10. The fingers 10 and 11 interdigitate as best seen in Fig. 8 so that tangential movement of the two pulley discs relative to each other is impossible.

It will be noted that the receding portions 12 opposite the projecting portions 13 do not follow the curvature of the projecting portions 13, as in the embodiment shown in Fig. 3. Consequently,the projections 13 on the pulley disc 6b, and the projections 14 on the pulley disc 6a constitute two sets of circumferentially spaced guiding means having guiding faces 13a and 14a, respectively, for guiding the filament 15. The inwardly located guiding face end portions 1311, 14a project into the spaces between the guiding means 14 and 13, whereas the outwardly located face end portions 13"a, 14"a are located on both sides of plane 60.

Similar to the embodiment shown in Fig. 5, radially projecting face portions 16 or supporting means having circumferentially spaced supported faces are provided for supporting the filament 15. Each of the projecting face portions 16 is partly formed by a projection or supporting face 16a on the pulley disc 6a and partly formed by a projection or supporting face 16b on the pulley disc 6b. The thread 15 is supported in the axial planes in which the fingers 11 engage the fingers 10. Therefore the edges of the projections 16a and 16b are rounded so that the thread of filament does not engage the edges of the fingers, which is particularly advisable when great forces are transferred to the filament since a certain slippage due to stretching of the filament is unavoidable.

Figs. 12, 12a, 12b, 13, 13a, and 13b illustrate an arrangement according to which the axial distance between the pulley discs 6a and 6b is adjusted by inserting spacing annular members 17, as shown in Figs. 12a and 13a; or 17a, as shown in Figs. 12b and 13b, respectively. In Figs. 12 and 13, the projections 13 and 14 overlap most, since no spacing member 17 is provided. Figs. 12a and b,

- and Figs. 13a and billustrate how the pulley discs are farther spaced from each other by spacing rings 17 and 17a so that the projections 14 and 13 define paths of lesser deflection for the rope or filament 15.

The coaxial pulley discs 6a and 6b each have claw means 10, 11, respectively, as shown in Fig. 8, which project each toward the other of the discs and are interengaged with each other for guiding the discs for axial movementrelative to each other. ripheral portions 13, 14, respectively, which together define; on the periphery of the pulley an annular, periphi The discs have pe eral wavy groove having an outwardly flaring and widening'cross-section. Portions 13 and 14 each have outwardly flaring lateral face portions 13a and 14a, respectively, which extend transverse to the pulley axis and bound the groove, as shown in Figs. 13, 13a and 13b.

Each of the lateral face portions 13a, 14a has radially spaced inner and outer guiding face portions 13a, 13"a and 14a, 14"a, the inner guiding face portions 13a and 14'aoverlapping to varied extents as shown in Figs. 12, 12a and 13a, depending on the presence or absence of a spacing means 17, as seen in Figs. 13 and 1351. In Figs. 12b and 13b, a larger spacing means 17a is shown decreasing the overlap.

The groove is also bounded by an annular bottom face 16 which is here shown as being formed from the circumferentially spaced bottom face portions 16a and 16b projecting radially from portions 14 and 13, respectively. Each of the portions 16a, 16b extends circumferentially through a distance substantially smaller than the distance between each guiding face of one disc and the next guiding face of the other disc and is spaced circumferentially a. substantial distance from and intermediate adjacent projecting guiding face portions.

Since the pulley or roller according to the present invention permits a slippage-free run of the filament without requiring several loops, the filament or rope can be highly tensioned without slipping. In the manufacture of artificial fibers the newly spun, or treated fiber can be guided by a roller according to the present invention, and it is possible to stretch the fiber by the use of grooved rollers according to the present invention having different diameters, and different peripheral speeds, respectively, without damaging or breaking the fiber since the groove according to the present invention supports the fiber without snagging.

In the textile industry a thread running over a roller according to the present invention can be stretched in a very convenient manner while being steamed, dried, or chemically treated. In the event that a pulley according to the present invention is employed in transmissions, a single loop of a rope assures a reliable transmission of force without requiring guide rollers or other tensioning means.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of grooved pulleys differing from the types described above.

While the invention has been illustrated and described as embodied in a pulley consisting of two coaxial pulley discs defining a wavy groove having a bottom face including projecting bottom face portions for supporting a filament, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for variousapplications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should andare intended to be comprehended within the meaning and range of equivalence of the following claims.

' What isclaimed as new and desired to be secured by Letters Patent is: i s s 1. A pulley formed with an annual wavy groove laterally bounded by a pair of opposite annular lateral faces, each of said lateral faces having, alternately arranged axially projecting and receding face portions, the projecting face portions of one of said lateral faces being located opposite the receding face portions of the other lateral face, said groove being also bounded by mannular bottom face including radially projecting bottom face portions, each of said projecting bottom fac' portions,

being located intermediate and spaced a substantial distance' from adjacent projecting face portions of said pair of lateral faces.

2. A pulley formed with an annular peripheral wavy groove, said groove having an outwardly flaring and.

Widening cross-section and being laterally bounded by. a pair of opposite annular lateral faces extending transverse to the pulley axis, each of said lateral faces having alternately arranged axially projecting and receding face portions, the projecting face portions of one of said lateral faces being located opposite the receding face portions of the other lateral face, said groove being also bounded by an annular bottom face including radially projecting bottom face portions, each of said projecting bottom face portions being located intermediate and spaced a substantial distance from adjacent projecting face portions of said pair of lateral faces.

3. A pulley formed with an annual peripheral wavy groove, said groove having an outwardly flaring and widening cross-section and being laterally bounded by a pair of opposite annular lateral faces extending transverse to the pulley axis, each of said lateral faces hav ing alternately arranged axially projecting and receding face portions and extending substantially corresponding to a sinus function, the projecting face portions of one of said lateral faces being located opposite the receding face portions of the other lateral face, said groove being also bounded by an annular bottom face including ra-- dially projecting bottom face portions, each of said pro-- jecting bottom face portions being located intermediate and spaced a substantial distance from adjacent projecting face portions of said pair of lateral faces.

4. A pulley having an annular peripheral face and comprising two sets of circumferentially spaced guiding means on said annular peripheral face, the guiding means' of one of said sets being arranged staggered relative to the guiding means of the other of said sets, said guiding means having guiding faces for guiding a flexible eiongated means, the guiding faces of each set of guiding means projecting alternately in opposite axial directions into the spaces between the guiding means of the other set of guiding means; and a set of circumferentially spaced radially projecting face portions on said annular peripheral face, each of said radially projecting face portions extending circumferentially through a distance substantially smaller than the distance between each guiding face of one set and the next guiding face of the other set, and being located circumferentially spaced a substantial distance from and intermediate the guiding faces of adjacent guiding means of said two sets of guiding means and adapted to support the flexible elongated means.

5. A pulley having an annular peripheral face and comprising two sets of circumferentially spaced guiding means on said annular peripheral face, the guiding means of one of said sets being arranged staggered relative to the guiding means of the other of said sets, said guiding means having guiding faces for guiding a flexible elongated means, the guiding faces of each set of guiding means being composed of guiding face portions located inwardly in radial direction and projecting alternately in opposite axial directions into the spaces between the guiding means of the other set of guiding means and of outer face portions located outwardly in radial direction and located on opposite sides and spaced from a plane passing through said annular peripheral face normal to the axis of said pulley; means supporting at least one of said sets of guiding means for movement in axial direction toward and away from the other of said sets of guiding means; and a set of circumferentially spaced radially projecting face portions on said annular peripheral face, each of said radially projecting face portions extending circumferentially through a distance substantially smaller than the distance between. each r a guiding face of one. set and the next guiding facev of the other, set, and being located circumferentially spaced a substantial distance from and intermediate the guiding faces of adjacent guiding means of said two sets of guiding means and adapted to support the flexible elongated means.

6.. A pulley comprising at least two coaxial pulley discs, each. of said pulley discs having one set of cir- Cumferentially spaced guiding means on the periphery thereof, the guiding means of one of said sets being arranged staggered relative to the guiding means of the other of said sets, said guiding means having guiding faces for guiding a flexible elongated means, said guiding faces having inner and outer ends in radial direction, the guiding faces of each set of guiding means projecting alternately in opposite axial directions into the spaces between the guiding means of the other set of guiding means; a set of circumferentially spaced radially projecting face portions on at least one of said pulley discs, said, radially projecting face portions extending circumferentially through a distance substantially smaller than the, distance between each guiding face of one set and the next guiding face of the other set, and being located circumferentially spaced a substantial distance from, and intermediate the guiding faces of adjacent guiding means of said two sets of guiding means, said face portions being located inwardly of said outer ends of said guiding faces. and outwardly of said inner ends of said guiding faces and adapted to support the flexible elongated means; and means guiding said pulley discs for axial movement relative to each other.

7. A pulley comprising at least two coaxial pulley discs, each of said pulley discs having one set of circumferentially spaced guiding means on the periphery thereof, the guiding means of one of said sets being arranged staggered relative to the guiding means of the other of said sets, said guiding means having guiding faces for guiding a flexible elongated means, said guiding faces having inner and outer ends in radial direction, the guiding faces of each set of guiding means projecting alternately in opposite axial directions into the spaces between the guiding means of the other set of guiding means; a set of circumferentially spaced radially projecting face portions on at least one of said pulley discs,

said radially projecting face portions extending circumferentially through a distance substantially smaller than the distance between each guiding face of one set and the, next guiding face of the other set, and being located circumferentially spaced a substantial distance from, and I intermediate the guiding faces of adjacent guiding means of said two sets of guiding means, said face portions being located inwardly ofsaid outer ends of said guiding faces and outwardly of said inner ends of said guiding faces and adapted to support the flexible elongated means; means guiding said pulley discs for axial movement relative to each other; a spacing member located between said pulley discs for spacing the same in axial direction so that said guiding faces of the guiding means on one of said pulley discs project into the spaces between the guiding means on the other of said pulley discs for a predetermined distance; and attaching means for attaching said pulley discs to each other.

8. A pulley comprising at least two coaxial pulley discs, each of said pulley discs having one set of circumferentially spaced guiding means on the periphery thereof, the guiding means of one of said sets being arranged staggered relative to the guiding means of the other of said sets, said guiding means having guiding faces for guiding a flexible elongated means, said guiding faces having inner and outer ends in radial direction, the guiding faces of each set of guiding means projecting alternately in opposite axial directions into the spaces between the guiding means of the other set of guiding means; a set of circumferentially spaced radially projecting-face portions on at least one of said pulley discs,

said. radially projecting face portions extending circumferentially throughv a distance substantially smaller than the distance; between each guiding face of one set and the next guiding face of the other set, and being located circumferentially spaced a substantial distance from, and intermediate the guiding faces of adjacent guiding means of said two sets of guiding means, said face portions being located'inwardly of said outer ends of said guiding faces and outwardly of said inner ends of said guiding faces and adapted to support the flexible elongated means; means determining the relative position of said pulley discs in axial direction; and attaching means for attaching said pulley discs to each other.

9. A pulley comprising at least two coaxial pulley discs, each of said pulley discs having finger means projecting in axial direction toward the other of said pulley discs and interengaged with the finger means of the samefor guiding said pulley discs for axial movement relative to each other, each of said pulley discs having one set of circumferentially spaced guiding means on the periphery thereof, the guiding means of one of said sets being arranged staggered relative to the guiding means of the other of said sets, said guiding means having guiding faces for guiding a flexible elongated means, said guiding faces having inner and outer ends in radial direction, the guiding faces of each set of guiding means projecting alternately in opposite axial directions into the spaces between the guiding means of the other set of guiding means; a set of circumferentially spaced radially projecting face portions on at least one of said pulley discs, said radially projecting face portions. extending circumferentially through a distance substantially smaller than the distance between each guiding face of one set and the next guiding face of the other set, and

being located circumferentially spaced a substantial distance from, and intermediate the guiding faces of adjacent'guiding means of said two sets of guiding means,

said face portions being located inwardly of said outer ends of said guiding faces and outwardly of said'inner ends of said guiding faces and adapted to support the flexible elongated means; a spacing member located be tween said pulley discs for spacing the same in axial direction; and attaching means for attaching said pulley discs to each other.

10. A pulley comprising two coaxial pulley discs, each of said pulley discs having a peripheral portion defining with the peripheral portion of the other pulley disc an annular peripheral wavy groove on the periphery of the pulley, said groove having an outwardly flaring and widening cross-section, said peripheral portions having a pair of opposite annular lateral faces extending trans verse tothe pulley axis and bounding said groove, each of said lateral faces being located on one of said pulley discs and having a set of circumferentially spaced. guiding face portions, the guiding face portions of each set projecting into the spaces between the guiding face portions of the other set, said groove being also bounded.

by an annular bottom face at least one of said peripheral portions including radially projecting circumferentially spaced bottom face portions, each of said projecting bottom face portions extending circumferentially through a distance substantially smaller than the distance between each guiding face of one set and the next guiding face of the other set, and being located circumferentially spaced a substantial distance from and intermediate adjacent projecting guiding face portions; and attaching,

means for. attaching said pulley discs to each other.

11. A pulley comprising two coaxial pulley discs, each of said pulley discs having a peripheral portion defining with the peripheral portion of the other pulley disc an annular peripheralwavy groove on the periphery of the pulley, said groove having an outwardly flaring and widening cross-section, said peripheral portions having a pairof opposite annular lateral faces extending transr verse to the pulley axis and bounding said groove, each' of said lateral faces being'located on one or said pulley discs and having a set of circumferentially spaced guiding face portions, the guiding face portions of each set projecting into the spaces between the guiding face portions of the other set, said groove being also bounded by an annular bottom face at least one of said peripheral portions including radially projecting circumferentially spaced bottom face portions, each of said projecting bottom face portions extending circumferentially through a distance substantially smaller than the distance between each guiding face of oneset and the next guiding face of the other set, and being located circumferentially spaced a substantial distance from and intermediate adjacent projecting guiding face portions; spacing means arranged between said pulley discs for spacing said guiding face portions a predetermined distance in axial direction; and attaching means for attaching said pulley discs to each other.

12. A pulley comprising two coaxial pulley discs, each of said pulley discs having finger mean projecting toward the other of said pulley discs and interengaged with the finger means of the same for guiding said pulley discs for axial movement relative to each other, each of said pulley discs having a peripheral portion defining with the peripheral portion of the other pulley disc an annular peripheral wavy groove on the periphery of the pulley, said groove having an outwardly flaring and widening crosssection, said peripheral portions having a pair of opposite lateral faces extending transverse to the pulley axis and bounding said groove, each of said lateral faces being located on one of said pulley discs and having a set of circumferentially spaced guiding face portions, the guiding face portions of each set projecting into the spaces between the guiding face portions of the other set, said groove being also bounded by an annular bottom face at least one of said peripheral portions including radially projecting circumferentially spaced bottom face portions, each of said projecting bottom face portions extending circumferentially through a distance substantially smaller than the distance between each guiding face of one set and the next guiding face of the other set, and being located circumferentially spaced a substantial distancefrom and intermediate adjacent projecting guiding face portions; spacing means arranged between said pulley discs for spacing said guiding face portions a predetermined distance in axial direction; and attaching means for attaching said pulley discs to each other.

13. A pulley comprising, in combination, two sets of circumferentially spaced guiding means on the periphery thereof, the guiding means of one of said sets of guiding means being arranged circumferentially staggered relative to the guiding means of the other of said sets, said guiding means having guiding faces having outer ends located spaced a first radial distance from the axis of the pulley, and inner ends located spaced a second smaller radial distance from the axis of the pulley, the guiding faces of each set of guiding means projecting alternately in opposite axial directions into the spaces between the guiding means of the other set of guiding means; and a set of circumferentially spaced supporting means having circumferentially spaced supporting faces extending in axial direction transverse to said guiding faces and being spaced from the axis of the pulley a distance shorter than said first radial distance and greater than said second radial distance, each of said supporting faces extending circumferentially through a distance substantially smaller than the distance between each guiding face of one set and the next guiding face of the other set, and being located circumferentially spaced a substantial distance from and intermediate the guiding faces of adjacent guiding means of said two sets of guiding means and adapted to support portions of the flexible elongated means located intermediate the portions of the same which are guided by said guiding faces.

'14. A pulley comprising, in combination, two sets of circumferentially spaced guiding means on the periphery thereof, the guiding means of one of said sets of guiding means being arranged circumferentially staggered relative to the guiding means of the other of said sets, said guiding means having guiding faces having outer ends located spaced a first radial distancefrom. the axis of the pulley, and inner ends located spaced a. second smaller radial distance from the axis of the pulley, the guiding faces of each set of guiding means projecting alternately in opposite axial directions into the spaces between the guiding means of the other set of guiding means, the axial distance beween the guiding faces of adjacent guiding means of said two sets of spaced guiding means increasing toward said outer ends of said guiding faces; and a set of circumferentially spaced supporting means having circumferentially spaced supporting faces extending transverse to said guiding faces and being spaced from the axis of the pulley a distance shorter than said first 1'adial distance and greater than said second radial distance, each of said supporting faces extending circumferentially through a distance substantially smaller than the distance between each guiding face of one set and the next guiding face of the other set, and being located circumferentially spaced a susbtantial distance from and intermediate the guiding faces of adjacent guiding means of said two sets of guiding means and adapted to support portions of the flexible elongated means located intermediate the portions of the same which are guided by said guiding faces.

15. A pulley comprising, in combination, two sets of circumferentially spaced guiding means on the periphery thereof, the guiding means of one of said sets of guiding means being arranged circumferentially staggered relative to the guiding means of the other of said sets, said guiding means having guiding faces having, outer ends located spaced a first radial distance from the axis of the" pulley, and inner ends located spaced a second smaller radial distance from the axi of the pulley, the guiding faces of each set of guiding means projecting alternately in opposite axial directions into the spaces between the guiding means of the other set of guiding means, the axial distance between the guiding faces of adjacent guiding means of said two sets of spaced guiding means increasing toward said outer ends of said guiding faces; and a set of circumferentially spaced supporting means having circumferentially spaced supporting faces extending in axial direction transverse to said guiding faces and being spaced from the axis of the pulley a distance shorter than said first radial distance and greater than said second radial distance, each of said supporting faces extending circumferentially through a distance substantially smaller than the distance between each guiding face of one set and the next guiding face of the other set, and being located circumferentially spaced a susbtantial distance from and intermediate the guiding faces of adjacent guiding means of said two sets of guiding means and adapted to support portions of the flexible elongated means located intermediate the portions of the same which are guided by said guiding faces.

16. A pulley comprising, in combination, two sets of circumferentially spaced guiding means on the periphery thereof, the guiding means of one of said sets of guiding means being arranged circumferentially staggered relative to the guiding means of the other of said sets, said guiding means having guiding faces having outer ends located spaced a first radial distance from the axis of the pulley, and inner ends located spaced a second smaller radial distance from the axis of the pulley, the guiding faces of each set of guiding means projecting alternately in opposite axial directions into the spaces between the guiding means of the other set of guiding means; a set of circumferentially spaced supporting means having circumferentially spaced supporting faces extending transverse to said guiding faces and being spaced from the axis of the pulley a distance shorter than said first radial distance and greater than said second radial distance, each of said supporting faces extending circumferentially through a distance substantially smaller than the distance between each guiding face of one set and the next guiding face of the other set, and being located circumferentially spaced a substantial distance from and intermediate the guiding faces of adjacent guiding means of said two sets of guiding means and adapted to support portions of the flexible elongated means located intermediate the portion of the same which are guided by said guiding faces; and means supporting at least one of said sets of guiding means for movement in axial direction relative to the other of said sets of guiding means.

17. A pulley formed with an annular wavy groove having a plurality of spaced crest portions alternately projecting axially in opposite directions, and said groove having an annular bottom face including spaced radially projecting bottom face portions, each of said projecting bottom face portions being located intermediate and spaced a substantial distance from two adjacent crest portions and extending circumferentially through'a distance substantially smaller than the circumferential distance between two adjacent crest portions to provide unobstructed spaces between each bottom face portion and the two adjacent crest portions between which it is located, whereby an elongated flexible element guided by the pulley will engage at one of its sides one of said crest portions, then with its bottom surface the next following bottom face portion, then with its opposite side the succeeding crest portion, then with its bottom surface the following bottom face portion, and then with its one side the next following crest portion, and so on. Y

18. A pulley formed with an annular wavy groove having a plurality of spaced crest portions alternately projecting axially in opposite directions, said groove having an annular bottom face including spaced radially projecting bottom face portions, each of said bottom face portions being located intermediate and spaced a substantial distance from two adjacent crest portions, and extending circumferentially through a distance substantially smaller than the circumferential distance between two adjacent crest portions to provide unobstructed spaces between each bottom face portion and the two adjacent crest portions between which it is located, whereby an elongated flexible element guided by the pulley will engage at one of its sides one of said crest portions, then with its bottom surface the next following projecting bottom face portion, then with its opposite side the succeeding crest portion, then again with its bottom surface the following projectin ottom face portion, and then with its one side t2 the succeeding crest portion, and so on; said groove having an outwardly flaring and widening cross section.

19. A pulley comprising, in combination, two sets of circumferentially spaced guiding means on the periphery thereof, the guiding means of one of said sets of guiding means being arranged circumferentially staggered rela tive to the guiding means of the other of said sets, said guiding means having guiding faces having outer ends located spaced a first radial distance from the axis of the pulley, and inner ends spaced a second smaller radial distance from the axis of the pulley, the guiding faces of each set of guiding means projecting alternately in opposite axialdirections into the spaces between the guiding means of the other set of guiding means; and a set of circumferentially spaced supporting means having circumferentially spaced supporting faces extending transverse to said guiding faces and being spaced from the axis of the pulley a distance shorter than said first radial distance and greater than said second radial distance, each of said supporting faces extending circumferentially through a distance substantially smaller than the distance between each guiding face of one set and the next guiding face of the other set, and being located circumferentially spaced a substantial distance from and intermediate the guiding faces of adjacent guiding means of said two sets of guiding means and adapted to support portions of a flexible elongated means located intermediate the portions of the same which are guided by said guiding faces whereby an elongated flexible element guided by the pulley will engage at one of its sides a guiding face of one. set, then with its bottom surface the next following supporting face, then at its, opposite side the succeeding guiding face of the other set, then again with it bottom surface the next following supporting face, and then again with its one side the succeeding guiding face of said one set, and so on.

References Cited in the file of this patent UNITED STATES PATENTS 

